A comparison of two types of preperitoneal mesh prostheses in stoma surgery: application to an animal model.

INTRODUCTION

The aim of this study is to compare the integration of two types of prostheses (high and low density, written as HD and LD, respectively) implanted around the stoma to reinforce the abdominal wall to prevent parastomal eventration. The surgical technique used for preperitoneal placement of the prostheses is also described.

MATERIALS AND METHODS

We performed terminal sigmoid colostomies on 16 porcine animals. In 8 of the animals, HD prostheses were placed around the stoma in preperitoneal position, while in the other 8, we implanted wide-pore LD prostheses using the same surgical technique. The following macroscopic variables were then measured: adhesion, extrusion, stenosis, and retraction. A morphological study was also carried out to evaluate the foreign body reaction and the formation of neovascularization and collagen. All animals were killed 3 months after surgery.

RESULTS

Differences were observed with regard to retraction (47 ± 17.8 % for HD vs. 55 ± 19.4 % for LD) and extrusion (50 % for HD vs. 0 % for LD). These differences did not reach statistical significance. There was a great amount of scarring for both types of prostheses, with stomal stenosis being observed in all cases. The number and consistency of intra-abdominal adhesions was low and similar for both types of prostheses. Neither eventration nor necrosis was observed for either type. With regard to the tissue response, we observed both fibrosis and calcification phenomena in the peristomal areas of the LD prostheses. In the HD group, there was both a lower scarring response and a higher foreign body response, with the areas of the prostheses remaining intact.

CONCLUSIONS

Both types of prostheses are appropriate for preperitoneal placement in the experimental model used, leading to few intra-abdominal adhesions. Still, due to their integration characteristics, LD prostheses are more appropriate for implanting around the colon since they do not seem to lead to extrusions. When using prostheses, however, it is also essential to consider the important phenomenon of retraction, which is more common with LD mesh.